Thermostatic control device



June 1929. e. A. ROBERTSHAW 1,715,950

THERMOSTATIC CONTROL DEVICE Filed April 21, 1927 2 Sheets-Sheet 1 Z5 Z4 Z5 INVENTOR June 4, 1.929. G. A. ROBERTSHAW 1,715,950

THERMOSTATIC CONTROL DEVICE.

Filed April 21, 1927 2 She etsSheet 2 llllliiH NH v INVENTOR W ,4 MW

Patented June 4, 1929.

UNITED STATES PATENT ,OFFICE.

GEORGE A. ROBERTSHAW,-OF GREENSBURG, PENNSYLVANIA.

ism with the flame that is mnanosa'a'ric con'rnoL DEVICE.

Application filed April 21;

This invention relates to thermostatic control devices and particularly to thermostatically controlled valves.

One object of my invention is to provide a thermostatic control device for a gas burner that shall extend in parallelism with but be spaced from the flame controlled by it Another object of my invention is to provide a burner thatshall be provided with a thermostatic regulator that extends into 'a flue or other device'in substantial parallelbeing controlled thereby.

Another object of my invention is to provide a casting for a thermostatic control device that shall be provided with a plurality of passageways extending in substantial parallelism but in spaced relation.

Another object of my invention is to provide a thermostatically controlled burner that shall have provision for closing a supply passage for fuel to the burner if the burner is extinguished, and that shall have provision independent of the thermostatic control for permitting re-ignition of the burner when the thermostatic controlling device is relatively cold.

A further object of my invention is to provide a casting for a thermostatic control device in which two parallel extending passageways are connected by a passageway extending at a distinct angle to the axes of the other passageways, and so' disposed that it may be formed by a suitable tool,-such as a drill, inserted into one of the parallel passageways.

In thermostatically controlled burners de, signed for use as pilot lights for gas burners, furnaces and the like, it is'desirable that the gas supplied to the burner shall be controlled by the temperature of the flame of the burner. Accordingly, the thermostatic regulator for such a burner may be disposed so as to extend into the zone of combustion of the burner. In certain classes of work, such as household appliances, in which the burner is subjected to wide variations in the temperature of the surrounding atmosphere, it is desirable that the thermostatic regulator may extend upwardly into the body of the material to be heated in order that it may register the true temperature of that body rather than that of the surrounding atmosphere.

Accordingly, I have provided a thermo- 1927. Serial No. 185,499.

static control device in which a casting'may be provided with parallel extending openings or passageways that are connected by other passageways disposed at angles to the axes of the main passageways. One of the main passageways may extend throughout the entire length of the casting and have provision at one end for connecting it to a source of fuel supply, such as a gas line, and the other end may have provision for the reception of a thermostatic regulator that controls the passage of fuel through at least one of the passageways leading to the second main passageway to which a suitable burner may be attached.

A manually-operated valve structuremay control another passageway leading to the second main passageway in order to permit a supply of gas to enter it when the thermostatic regulator is operative to close the passageway controlled by it.

In order to simplify the process of casting the base member, I dispose one of the secondary passageways at an angle to the axes of the main passageways and at such a position that it may be formed by the use of a drill inserted into the second main passageway. This disposition of the passageway eliminates the necessity for ,any external plugs connecting the two main passageways.

In the accompanying drawings, I

Figure 1 is a view, partially in elevation and partially in section, of an illustrative embodiment of my invention in the open position;

Figure 2 is a similar view of the device in its closed position;

Figure 3 is a view, partially in elevation and partially in section, of the application of the thermostatic control device to a flue;

Figure 4 is a plan view of a gas burner with which the thermostatic control device may be utilized as a pilot light; and

Figure 5 is a view, partially in elevation and partially in section of a modified form of my invention.

In the illustrative embodiment of my in-- vention, the thermostatic control device 2 comprises a main casting 3 provided with two main parallel extending openings or passageways 4 and 5 separated by a wall 6 through which secondary passageways 7 and 8 may extend. The passageway 4 may be internally threaded at the upper end 9 for the reception of a thermostatic regulator 11, and the other end may be either externally or internally threaded for connection to a source of fuel supply such as a gas main, not shown. v

The passageway 5 is closed'at its lower end and may be internally threaded at its upper end for the reception of any suitable gas burner 12. The gas burner 12 is provided with suitable openings 13 and a band 14 for regulating the amount of primary air mixed with the gas. It is to be understood that the type of burner may be varied in accordance with the t pe of flame that the burner is required to develop.

The thermostatic regulator 11 may be constituted by an outer cylindrical shell 15 of aluminum or other material having a high coefficient of expansion. The upper end of the shell 15 is provided with internal threads 16 for the reception of one end of rod 17 of iron or other suitable material, having a low coefficient of expansion. A look nut 18 may be threaded onto the rod 17 after the position of the latter has been adjusted. The lower end of the rod 17 actuates a suitable valve 19 cooperating with the shoulders 21 formed within the passageway 4 and 0011- stituting a valve seat. The valve seat should preferably be placed below the auxiliary passageway 7 in order to prevent the passage of gas thereto when the thermostatic regulator 11 is in its closed position.

The auxiliary passageway 8 may be disposed at right angles to the main passageways 4 and 5 and centered with respect to an opening 22 formed in the casting 3. The opening of the passageway 8 into the passageway 4 may be machined in order to constitute a valve seat 23 for the reception of a valve 24 that may be inserted through the opening 22, and held in a closed position by coil spring 25 bearing against a suitable packing gland 26 that closes the opening 22.

In the operation of the thermostatic control device the valve 24 is manually opened whereupon gas is permitted to flow through the lower portion of the main passageway 4, auxiliary passageway 8 and the main passageway 5 to the urner where it is ignited. The valve 24 is held open a sufficient length of time to permit the thermostatic regulator 11 to become warm enough so that the al'uminum shell expands relatively to the iron rod 17 and raises the valve 19 from its seat 21. Thereafter, gas traverses the lower portion of the main passageway 4, the seat 21, the auxiliary passageway 7 and the main passageway 5 to the burner 12. The valve 24 may then be released to close the auxiliary passageway 8.

So long as the thermostatic regulator 11 continues to be heated by the flame from the burner 12, the valve 19 remains open thereby permitting gas to flow through the casting 3 to the burner 12. Should the flame be extinguished, the aluminum shell 15 cools and contracts, thereby forcin the valve 19 against its seat 21, shutting off the supply of gas to the burner 12. Should the temperature of the burner become exceedingly low the iron rod 17 may be deformed to compensate for the excessive shrinkage of the aluminum shell 15, as is shown in Figure 2, without injury to the latter or the valve seat 21. The valve is preferably so shaped that irrespective of deformation of the rod 17, a proper seating of the valve takes place. This may be-accomplished by the use of a special valve as illustrated.

The present invention is particularly useful in connection with apparatus requiring the burning of a small amount of gas in fines, such as for example in connection with gas-fired refrigerators of the absorption type, as indicated in Figure 3. In such constructions when the thermostatic regulator 11 is extended into a fine 31 beyond the flame of the burner 12, the former is actuated in accordance with the temperature of the material adjacent to the walls of the flue rather than by ambient room temperature as is the case where a major portion of the thermostatic regulator 11 is disposed be low the burner 12.

Referring to Figure 4, my thermostatic control device may also be applied to gas furnaces, heaters and the like for use as a pilot light.

Referring to Figure 5, I have shown a modified form of my invention in which a ring burner 35 surrounds the thermostatic regulator 11 instead of being disposed at one side thereof as is shown in the other form of my invention. The burner 35 is disposed relatively near the end of the thermostat 11, and in order to insure a rapid heating of the latter I have provided a tube 36 fitted over and extending beyond the thermostatic regulator 11 for concentrating and transferring heat from the burner 35 to the thermostatic regulator 11. The tube 36 may be of ordinary steel or may be of a suitable non-oxidizing material, as its coefiicient of expansion has nothing to do with the functioning of the thermostatic regulator 11. If steel is used, the tube 36 may be replaced from time to time, while if a non oxidizing material is used, the thermostat may remain in use indefinitely.

In the operation of this form of my invention, the flame 37 from the burner 36 impinges upon the tube 36 and heats the latter which heat is transferred to the upper end of the cylindrical shell 15 which governs the operation of the thermostatic regulator in a manner similar to that "shown in Figures 1 and 2. By reason of the provision of the tube 36, the shell 15 of the thermostatic regulator is not affected by the flame 37 Accordingly --I have provided a thermostatic control device that is constituted by a A is extinguished. A suitable manually-opera-ted valve is provided in the casting to permit a burner to be lighted by bypassing the passageway controlled by the thermostatic regulator. The thermostatic regula tor and the burner preferably extend outwardly in the same direction and in parallelism to each otlier but in s aced relation in order that the material 0 the thermostatic regulator shall be-kept out of the zone of combustion thereby prolonging its life.

Another feature of my invention is the use of passageways for connecting the main passageways that may be drilled from the mouth of the passageway connected with the burner, thereby rendering it unnecessary to provide external plugs in the casting 3.

It is to be understood that various changes in the configuration, size and disposition of the'component parts of my inventionlmay be made without departing from the scope of the appended claims.

I claim v 1. In a thermostatic control device, a base, a passageway extending therethrough and having a valve seat formed therein, means for connecting the passageway to a source of fuel, a thermostatically controlled valve cooperating with the valve seat, a second passageway extending in substantial parallelism t0 the first passageway and terminating in a burner, connecting passageways between the first and second named passageways disposed on opposite sides of the valve 'seat, and means normally closing the connecting passageway disposed between the source 0 fuel and-the valve seat, whereby the fuel supplied to the burner is normally dependent-upon the positions of the thermostatically controlled valve.

2. In a thermostatic control device, a base, a passageway extending therethrough and having a valve seat formed therein, means for connecting the passageway to a source of fuel, a thermostatically controlled valve cooperating with the valve seat, a second main passageway formed in the. base and terminating in a burner, connecting pas-.

sageways between the first and second named passageways disposed 'on opposite sides of the Valve seat, and means normally closing the connecting passageway disposed between the source of fuel and the valve seat, where-- by the fuel supplied to the burner is normally dependent upon the position of the thermostatically controlled valve.

3. In a thermostatic control device, a base, a passageway extending therethrough and having a valve seat formed therein, means for connecting the passageway to a source of fuel, a thermostatically controlled valve cooperating with the valve seat, a second main passageway formed in the base and communicating with a burner, connecting passageways between the first and second named passageways effective on opposite sides of the valve seat, and means normally closing the connectlng passageway disposed between the source of fuel and the valve seat, whereby the fuel supply to the burner is normally dependent upon the position of the thermostatically controlled valve.

4. In a thermostatic control device, a base, a passageway extending therethrough and having a valve seat formed therein, means for connecting the passageway to a source of fuel, a thermostatically controlled valve cooperating with the valve seat, a

second main passageway formed in the base and communicating with a burner, connecting passageways between the first and second named passagewayseflective on opposite sides of the valve seat, whereby said 'valve controls the movement of fuel through one of said connecting passageways and another connecting passageway serves as a by-pass to said valve.

In testimony whereof I have hereunto set my hand.

GEORGE A. ROBERTSHAW. 

